Modulating the polarization of a beam of quantum particles is a powerful method to tailor the macroscopic properties of the ensuing energy flux as it directly influences the way in which its quantum constituents interact with other particles, waves or continuum media. Practical polarizers, being well developed for electric and electromagnetic energy, have not been proposed to date for heat fluxes carried by phonons. Here we report on atomistic phonon transport calculations demonstrating that ferroelectric domain walls can operate as phonon polarizers when a heat flux pierces them. Our simulations for representative ferroelectric perovskite PbTiO3 show that the structural inhomogeneity associated to the domain walls strongly suppresses transverse phonons, while longitudinally polarized modes can travel through multiple walls in series largely ignoring their presence.
@article{arxiv.1710.00663,
title = {The ferroelectric domain wall phonon polarizer},
author = {Miquel Royo and Carlos Escorihuela-Sayalero and Jorge Íñiguez and Riccardo Rurali},
journal= {arXiv preprint arXiv:1710.00663},
year = {2017}
}